Lisa Kudrow and Mira Sorvino—riding high on the success of Friends and Mighty Aphrodite, respectively—were perfectly matched as the eponymous stars of Romy and Michele’s High School Reunion, an R-rated 1997 comedy about a pair of ditzy 28-year-olds who share a bedroom in Venice Beach, love Pretty Woman, and design idiosyncratic fashions. Directed by David Mirkin, the movie grossed $29 million when it premiered 20 years ago, against a $20 million budget—a whopping $240,000 of which went toward licensing “Time After Time.” Though the film wasn’t an immediate hit, it eventually achieved cult status on video and cable reruns, thanks to its charming stars, its unique wit (“Do you have some sort of . . . business woman’s special?”), and the heartwarming friendship at its core.

But Romy and Michele’s story actually began more than 10 years earlier. In 1987, Romy and Michele scribe and co-executive producer Robin Schiff decided to add a pair of overgrown Valley girls to a play she had written, Ladies Room. Kudrow, whom Schiff knew from the Groundlings improv comedy troupe, played Michele; it was her very first role in a professional production.

“They were loosely based, just visually, on these girls I used to see going into a club on Sunset Blvd.,” Schiff says. “You’d see these two friends, and they looked like they got dressed together and were wearing different versions of the same thing.” She was shocked to see the characters earn “a huge laugh and applause” on opening night from their entrance alone: “I’m standing in the theater going, why? I’m still fascinated what made them applaud just by seeing them.” And the laughs kept coming—especially when Romy admitted that she hates throwing up in public, and Michele replied, “Me too.”

“I knew it was funny, but when Lisa did it, it gave me a billion ideas from her saying two words,” Schiff says. “I knew no matter what I wrote Lisa would kill it. Then I really started hearing her.”

Kudro and Schiff’s partnership evolved into a pilot called Just Temporary (it didn’t get picked up), then another run of the play. Meanwhile, two execs at the Disney subsidiary Touchstone were looking for a “female version of Wayne’s World” when they read Ladies Room. Schiff was initially reluctant to adapt it into a screenplay: “There was stuff that wasn’t going to translate into a movie,” she says. Eventually, though, she thought about Romy and Michele being invited to their reunion—“and it wasn’t until they fill out the questionnaire when they realize their lives hadn’t amounted to anything. That seemed funny to me.”

The script took five years to develop; if not for Kudrow’s subsequent Friends stardom, Schiff has doubts the movie would have gotten made at all. Even after it was completed, Schiff had a hunch Romy and Michele would be a box-office stinker. According to her, it was “one of the lowest-tested movies in the history of Disney.” Certain scenes were recut, but people still “thought it was dumb.”

“The studio was going to dump it,” Schiff says. “I made plans to go out of town the weekend it opened, because I figured there would be all these horrible reviews and I’d be embarrassed.” When Disney suddenly moved the film’s planned release date back to accommodate Grosse Pointe Blank—another high-school reunion comedy, starring John Cusack—Schiff was stuck at home. “And the reviews start coming out,” she remembers, “and they were good!” (Ebert gave it three stars and two thumbs up.) “We all were in an unbelievable state of shock.” Both Grosse Pointe and Romy and Michele ended up being profitable at the box office.

Schiff thinks she wrote an “original” story in Romy and Michele, but also understands why some people might not like the movie. “I was there for the shooting of the dance”—a bizarre sequence that could give the Movements from The OA a run for their money, set to the very expensive “Time After Time”—“and I’m going, what the hell are they doing? The first time I saw it cut together, I didn’t know what to think. The longer it went on, the funnier it got.”

Twenty years later, the film’s depiction of genuine female friendship is key to its appeal. It was driven more by character than plot, and ridiculous as they are, those characters also feel real—perhaps because Schiff based her protagonist on her relationship with her best friend. “One day we were stuck on a plane on a tarmac, and started reading the Sky Mall catalog and laughing our asses off,” she said. “That was the kind of friend you want to hang out with—that even stuck on a plane on the tarmac you can still have fun.”

Last month in L.A., Schiff and Sorvino attended a 20th anniversary screening of the film. Sorvino told Schiff that she wants to do a sequel, but though Schiff already wrote and directed a critically drubbed Romy and Michele prequel for ABC Family in 2005—starring Katherine Heigl and Alexandra Breckenridge as the title characters—she thinks a true sequel will never happen. Schiff also believes a studio would never greenlight a movie like Romy and Michele today. Her original film, she says, was “so low-concept”—unlike today’s comedies, which are not just high-concept, but also “gross. Not even crude, but gross.”

Schiff’s been living with Romy and Michele for nearly 30 years, but this summer will mark a new milestone for the characters: she’s bringing a musical version of Romy and Michele to the stage, at Seattle’s 2,000-seat 5th Avenue Theatre. Kristin Hanggi, director of Broadway’s Rock of Ages, is directing, while actors Cortney Wolfson and Stephanie Renee Wall play Romy and Michele, respectively. Orange Is the New Black and Weeds composers Gwendolyn Sanford and Brandon Jay wrote the music and lyrics to songs like “Business Woman Special,” “10 Years,” “I Invented Post-Its,” and “Changing Lives One Outfit at a Time.”

So, what does Schiff think the girls would be doing today—besides starring in a musical with Broadway ambitions? “I don’t know,” she says. “It’s hard to picture them getting married and having kids. But what else have they been doing then if they’re still living together? I like to believe that they’re doing well with their store, and maybe they’re bigger fashion designers. I know for a fact Michele is not with Sandy [played in the film by Alan Cumming]. That was a big mistake.”

No matter what shenanigans Romy and Michele would be entangled in now, the film has touched people—an outcome Schiff never foresaw. Schiff thinks the movie “makes people feel good.” She’s had fans tell her it helped them cope with their depression. A veteran told her he was closeted while stationed on a submarine, and would comfort himself by watching Romy and Michele in his bunk. “Sometimes I’m going, who thought I’d be spending a big portion of my life writing this?” she says. ” But that’s just the way it’s worked out."